PLATE XLVIL 
Figs. 1, 2. Molgula carpenteri, n. sp. 
Figs. 3-5. Polycarpa aspera, n. sp. 
Fig. 6. Baihyoncus discoideus, n. sp. 
Figs. 7-10. Baihyoncus minutus, n. sp. 
Fig. 11. Ascidia scabra (f), 0. F. .Miiller. 
at. Atrial aperture. 
hr. Branchial aperture. 
g. Keproductive organs. 
i. Intestine. 
m.h. Muscle bands. 
01. (Esophagus. 
sg. Stigmata of branchial sac. 
st. Stomach. 
tn, in'. Large and small tentacles. 
tr, tr', tr". Transverse vessels of branchial 
sac. 
Fig. 1. Specimen of Molgula carpentcri, seen from side ; natural size. 
Fig. 2. Part of tlie brancMal sac of Molgula carpenteri, seen from the inside ; magnified 
(S., 1 inch). 
Fig. 3. Specimen of Polycarpa aspera ; natural size. 
Fig. 4. Part of the branchial sac of Polycarpa aspera, seen from inside ; magnified 
(S., 1 inch). 
Fig. 5. Tentacles of Polycarpa aspera; magnified (S., 1 inch). 
Fig. 6. Diagram showing the course of the alimentary canal in Baihyoncus discoideus ; 
natural size. 
Fig. 7. Specimen of Baihyoncus minutus ; natural size. 
Fig. 8. Alimentary canal of Baihyoncus minutus; magnified (S., 1 inch, reduced). 
Fig. 9. Branchial aperture, &c., of Baihyoncus minutus, seen from the inside, showing 
tentacles, muscle bands, &c. ; highly magnified (S., \ inch). 
Fig. 10. Atrial aperture, &c., of Baihyoncus minutus, seen from the inside, showing 
muscle bands ; highly magnified (S., inch). 
Fig. 11. Specimen of Ascidia scabra {?), 0. F. Muller, with test removed, seen from 
right hand side, showing enlarged atrial siphon ; natural size. 
